1. Give players the option in gameplay menu to autopause when ping check (already there) gets red.
2. Don't close the game for 5min if no client response comes back (dedicated games already exist in multiplayer).
3. In MP let the party leader decide if autopause is on or not - similar to mp selection.
4. If player doesn't come back, resume game with 30sec gameplay. If the player dies its okay. You need that to avoid abuse of the feature.
My feeling is that Blizzard doesn't give much about HC players. After the inital purchase they won't generate additional value. If HC players die in HC, they "maybe" tend to play SC instead -> more profit for Blizzard. I'd rather quit the game, if my top ten HC deaths all result from d/c-ing.
Vote +1 and sticky if you like it.